HPSudip

Thanks @HPNavjot , as discussed with @HPRoss , lets remove attributes support from the library only when it becomes `obsolete`.

It seems, we need to put `@set:JvmSynthetic` in the Kotlin code for these variables so that Java can only see and call the builder setters.

This is taken care and available in the latest release. Hence closing.

Fix present in v0.7.16. Hence closing.